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Differential D9581

copies: document the current algorithm step
ClosedPublic

Authored by marmoute on Dec 14 2020, 5:51 AM.

Details

Reviewers
Alphare
pulkit
Group Reviewers
hg-reviewers
Commits
rHG70a9eb899637: copies: document the current algorithm step
Summary

We are about to reorganise everything and we document the "old" way to clarify
the change that leads to the "new way".

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

marmoute created this revision.Dec 14 2020, 5:51 AM
baymax updated this revision to Diff 24232.Dec 14 2020, 7:05 AM

✅ refresh by Heptapod after a successful CI run (🐙 💚)

Alphare accepted this revision.Dec 14 2020, 8:06 AM
baymax updated this revision to Diff 24350.Dec 17 2020, 3:26 PM

✅ refresh by Heptapod after a successful CI run (🐙 💚)

pulkit requested changes to this revision.Dec 18 2020, 4:03 AM
pulkit added a subscriber: pulkit.
pulkit added inline comments.
mercurial/copies.py
369

If I am correct, the -> is a utf8 here.
#coding utf8 is added in next patch.

This revision now requires changes to proceed.Dec 18 2020, 4:03 AM
baymax updated this revision to Diff 24379.Dec 18 2020, 8:15 AM

✅ refresh by Heptapod after a successful CI run (🐙 💚)

marmoute added inline comments.Dec 18 2020, 9:27 AM
mercurial/copies.py
369

good catch.

marmoute added a commit: rHG70a9eb899637: copies: document the current algorithm step.Dec 18 2020, 3:05 PM
This revision was not accepted when it landed; it landed in state Needs Review.
Closed by commit rHG70a9eb899637: copies: document the current algorithm step (authored by marmoute). · Explain Why
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mmercurial/copies.py (14 lines)

Diff 24421

mercurial/copies.py

# coding: utf8
# copies.py - copy detection for Mercurial # copies.py - copy detection for Mercurial
# #
# Copyright 2008 Matt Mackall <mpm@selenic.com> # Copyright 2008 Matt Mackall <mpm@selenic.com>
# #
# This software may be used and distributed according to the terms of the # This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version. # GNU General Public License version 2 or any later version.
from __future__ import absolute_import from __future__ import absolute_import
if rustmod is not None and alwaysmatch: if rustmod is not None and alwaysmatch:
return rustmod.combine_changeset_copies( return rustmod.combine_changeset_copies(
list(revs), children, targetrev, revinfo, isancestor list(revs), children, targetrev, revinfo, isancestor
) )
isancestor = cached_is_ancestor(isancestor) isancestor = cached_is_ancestor(isancestor)
all_copies = {} all_copies = {}
# iterate over all the "parent" side of copy tracing "edge"
for r in revs: for r in revs:
# fetch potential previously computed data for that parent
copies = all_copies.pop(r, None) copies = all_copies.pop(r, None)
if copies is None: if copies is None:
# this is a root # this is a root
copies = {} copies = {}
# iterate over all known children to chain the existing data with the
# data from the parent → child edge.
for i, c in enumerate(children[r]): for i, c in enumerate(children[r]):
p1, p2, changes = revinfo(c) p1, p2, changes = revinfo(c)
childcopies = {} childcopies = {}
# select the right parent → child edge
pulkitUnsubmitted
Not Done

If I am correct, the -> is a utf8 here.
#coding utf8 is added in next patch.

pulkit: If I am correct, the `->` is a utf8 here. `#coding utf8` is added in next patch.
marmouteAuthorUnsubmitted
Done

good catch.

marmoute: good catch.
if r == p1: if r == p1:
parent = 1 parent = 1
if changes is not None: if changes is not None:
childcopies = changes.copied_from_p1 childcopies = changes.copied_from_p1
else: else:
assert r == p2 assert r == p2
parent = 2 parent = 2
if changes is not None: if changes is not None:
childcopies = changes.copied_from_p2 childcopies = changes.copied_from_p2
if not alwaysmatch: if not alwaysmatch:
childcopies = { childcopies = {
dst: src for dst, src in childcopies.items() if match(dst) dst: src for dst, src in childcopies.items() if match(dst)
} }
# chain the data in the edge with the existing data
newcopies = copies newcopies = copies
if childcopies: if childcopies:
newcopies = copies.copy() newcopies = copies.copy()
for dest, source in pycompat.iteritems(childcopies): for dest, source in pycompat.iteritems(childcopies):
prev = copies.get(source) prev = copies.get(source)
if prev is not None and prev[1] is not None: if prev is not None and prev[1] is not None:
source = prev[1] source = prev[1]
newcopies[dest] = (c, source) newcopies[dest] = (c, source)
assert newcopies is not copies assert newcopies is not copies
if changes is not None and changes.removed: if changes is not None and changes.removed:
if newcopies is copies: if newcopies is copies:
newcopies = copies.copy() newcopies = copies.copy()
for f in changes.removed: for f in changes.removed:
if f in newcopies: if f in newcopies:
if newcopies is copies: if newcopies is copies:
# copy on write to avoid affecting potential other # copy on write to avoid affecting potential other
# branches. when there are no other branches, this # branches. when there are no other branches, this
# could be avoided. # could be avoided.
newcopies = copies.copy() newcopies = copies.copy()
newcopies[f] = (c, None) newcopies[f] = (c, None)
# check potential need to combine the data from another parent (for
# that child). See comment below for details.
othercopies = all_copies.get(c) othercopies = all_copies.get(c)
if othercopies is None: if othercopies is None:
all_copies[c] = newcopies all_copies[c] = newcopies
elif newcopies is othercopies: elif newcopies is othercopies:
# nothing to merge: # nothing to merge:
pass pass
else: else:
# we are the second parent to work on c, we need to merge our # we are the second parent to work on c, we need to merge our
else: else:
# we do not know if the other dict is a copy or not, so we # we do not know if the other dict is a copy or not, so we
# need to blindly copy it. Future change should make this # need to blindly copy it. Future change should make this
# unnecessary. # unnecessary.
minor, major = newcopies, othercopies.copy() minor, major = newcopies, othercopies.copy()
copies = _merge_copies_dict(minor, major, isancestor, changes) copies = _merge_copies_dict(minor, major, isancestor, changes)
all_copies[c] = copies all_copies[c] = copies
# filter out internal details and return a {dest: source mapping}
final_copies = {} final_copies = {}
for dest, (tt, source) in all_copies[targetrev].items(): for dest, (tt, source) in all_copies[targetrev].items():
if source is not None: if source is not None:
final_copies[dest] = source final_copies[dest] = source
return final_copies return final_copies
def _merge_copies_dict(minor, major, isancestor, changes): def _merge_copies_dict(minor, major, isancestor, changes):